An optimization framework for capacity planning of island electricity systems

Meeting decarbonization goals requires taking significant action on electricity systems, which are a major source of CO2 emissions. Decarbonizing island electricity systems raises additional challenges due to their heavy historical dependence on fossil fuels and strict power-reserve and reliability requirements. To address this challenge, this paper presents a comprehensive optimization model for long-term capacity planning of island electricity systems. Our model determines an optimal mix of generation and transmission capacity to satisfy energy demand at least cost while respecting the strict technical constraints that are inherent in island systems. In addition, our model considers the use of thermal and renewable generation, electric vehicles providing electricity-system services, batteries, pumped-hydroelectric storage, and ac and high-voltage dc transmission lines.We demonstrate our model with a case study of the Canary Islands archipelago. Our results show that combining the aforementioned technologies reduces generation costs by up to 25% and capacity requirements up to 50% (relative to a case without the technologies). In addition, without any mechanism to internalize the social cost of carbon, fossil-fueled thermal generation is the lowest-cost source of energy. Environmental considerations demonstrate the benefits of renewable generation and result in these carbon-free energy sources supplying about 40% of the energy mix.

Automated summary

Meeting decarbonization goals for island electricity systems requires a comprehensive optimization model that considers both technical constraints and cost considerations. This paper presents such a model and demonstrates its effectiveness through a case study of the Canary Islands archipelago. By combining thermal and renewable generation, electric vehicles, energy storage, and transmission lines, it is possible to significantly reduce generation costs and capacity requirements while increasing the share of carbon-free energy sources in the energy mix.